[R] running a long R process on Linux using putty - best practice to disconnect

[Martin Tomko]

Dear all,
I am sure this has been solved before, googling did not help much,. 
Warning, I am not great with putty/linux servers

Situation: I have been given access to an R installation on a Linux 
server to do some larger number crunching that was killing my machine. I 
use putty to connect, and then go R, source("myscript") and all is fine
But this will take potentially days, and I would like to disconnect

What is the best practice? Someone mentionne nohup, but this would 
require starting the R script with an argument to R, I think. Is this 
doable?

Another option was using screen, btu that is not available on the server.
Any help is welcome.

Thanks
Martin